The 49ers have gained 2,280 rushing yards this season. The Seahawks have gained 2,250. That's good for second and third in the league.

This is the story of the NFC West, suddenly home to the NFL's two toughest teams. San Francisco narrowly leads Pete Carroll's crew, but the teams are mirror images. And Seattle is closing fast.

"I think we are similar," Carroll said this week. "I can't help but see that. Because they believe in playing big-time defense, which we do. They believe in the running game, which we do. They have a very strong emphasis on special teams, which we do.

"I think that's really the three pillars of what we're trying to put together here. That's what I know we're dealing with. And I don't know how they speak it or how Jim talks about it. But it's certainly what's obvious about their team when you have to line up against them."

You'll notice Carroll didn't even mention the quarterback position, which is such a Pete Carroll thing to do. That's where we'll start our look at these two Super Bowl contenders who meet Sunday night and really are more similar than different.

Kaepernick has thrown more than 25 passes only once in five starts (Wilson averages 25). Kaepernick has a stronger arm than Wilson and also looks to run more quickly. Wilson tends to escape pass rushers while still trying to make a play throwing. He throws away a lot of passes.

The Seahawks really run a conservative offense that dials up a handful of big-shot plays during the game. Wilson has improved throwing intermediate routes, but they're still not the offense's bread and butter. The 49ers' offense is more varied week to week and tougher to prepare for. The 49ers made Kaepernick the starter with the idea of adding a big-play element, and it's mostly worked. He can make throws Alex Smith can't make.

San Francisco has shied away from over-reliance on Kaepernick as a runner. The 49ers have mostly kept him in the pocket by design. We wonder if they will uncork a lot of zone-read plays Sunday night against a familiar opponent.

This could be one of the defining quarterback rivalries of the next decade. Kaepernick and Wilson aren't going anywhere.

The power runners

Marshawn Lynch remains the fulcrum the Seahawks' offense is built around. It's amazing that the league's second-leading rusher was viewed as a possible washout before he came to Seattle. He still runs every play like it's his last. Lynch and the 49ers' Frank Gore both rank in the top five in the league in yards after contact, according to Pro Football Focus.

Whereas Lynch's approach is unbridled aggression, Gore is more versatile. He's a better blocker and one of the best receiving running backs of the last decade. He still can be shifty for his size, although he doesn't run away from defenses as often. Backup LaMichael James has been seamlessly integrated into the 49ers' offense since the season-ending injury to backup Kendall Hunter. James' speed and versatility paired with Kaepernick could be tough for Seattle's defense to handle.

The 49ers probably have the toughest running game to prepare for in the league. We don't think any offense lines up in as many different formations with as many different personnel. They do a lot of motion before the snap that stresses the defense. Their playbook is seemingly endless, and Gore handles it all well. His yards-per-carry average is higher than it's been since 2006.

The pass rushers

No team is better at defensive line stunts than the 49ers. Aldon Smith and Justin Smith are poetry in motion, which is one reason why Justin Smith's potential absence Sunday night would be very painful for San Francisco. Defensive end Ray McDonald has enjoyed a very underrated season, and Ahmad Brooks blitzes well from the linebacker position.

Seattle has a unique style that tailors very specific roles to each of its players. Chris Clemons easily is the Seahawks' most consistent pass rusher, while Bruce Irvin does a nice job on clear passing situations. Alan Branch and Red Bryant also can create pressure. The loss of Jason Jones to injury shouldn't be understated. He was playing very well for Seattle.

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The 49ers are known for their two inside linebackers, Patrick Willis and Navorro Bowman. Both possess a combination of speed, power and instincts that is rare. The Seahawks have one middle linebacker in their 4-3 defense, but rookie Bobby Wagner already is approaching the level of Willis and Bowman. Seriously. He has a different style of playing -- flying all over the field -- but he's a ton of fun to watch. Just keep an eye on him Sunday night, and you'll see. He's our pick for Defensive Rookie of the Year.

Big-hitting secondary

Seattle's defense is built around its physical secondary. It looks like cornerback Richard Sherman will be available for the game; he's appealing a four-game suspension for PEDs. Teammate Brandon Browner currently is serving a suspension.

The Seahawks' group -- including safeties Earl Thomas and Kam Chancellor -- gets a lot of attention, but don't overlook the 49ers' secondary. Second-year pro Chris Culliver is enjoying an excellent season at cornerback. Donte' Whitner is good for a huge hit or two at safety every week, and Dashon Goldson is extremely versatile. Both defenses have players who know their roles well.

The new black and blue division

Seattle and San Francisco both have enough firepower to make it to the Super Bowl, but first, they have to decide what team will hit the NFC playoffs with huge momentum. A loss by the 49ers likely would knock them out of position for a playoff bye. That would make San Francisco's Super Bowl path much, much tougher. It also could set up a 49ers-Seahawks rubber match in two weeks in San Francisco.